The present invention generally relates to hand tools for use in the construction and building industry. More particularly, the present invention relates to a hand tool suitable for use in lifting and carrying building blocks, such as those made of concrete or cinder and having apertures, referred to as open cells, therethrough.
The traditional building block is the familiar brick which is small enough to be handled manually without difficulty. However, with the advent of larger blocks, such as cinder or concrete blocks, the relative size of the block makes it difficult to handle the blocks with a single hand, and in consequence both hands must be used to lift the block onto mortar on the end or top of the wall being built. Of course, this is undesirable as the mason would prefer to have the trowel or other tool in one hand while positioning the block with the other.
Without the use of a tool, the mason or workman must pick up the block directly from a flat surface, such as the ground or a stack of such blocks, requiring the worker to stoop and get his fingers under the block in order to lift it. Such blocks are not only relatively heavy, but have very rough surfaces. This can damage bare hands over time. Even when hands are protected by gloves, the gloves are susceptible to rapid wear.
Accordingly, there have been devised a variety of tools for lifting such blocks. For example, U.S. Pat. No. 4,982,987 to Riggins et al., discloses a masonry block tool for picking up and transporting masonry blocks. However, the worker must use a pair of cross-handle members, one in each hand, in order to lift and carry a single block.
U.S. Pat. Nos. 2,652,278; 2,821,426; and 3,237,979 all disclose hand tools for lifting and carrying such blocks. However, these tools grasp the block by frictional engagement between an outer surface of the block and an inner surface within the cell, or a cross-member of the block between two cells. Problems presented with such devices are that the wall thickness of these blocks is not consistent. Thus, these devices include relatively complicated mechanisms for adjusting the device to fit the various widths of the various blocks used. Of course, this presents increased manufacturing costs, as well as increased complication in using the tool.
U.S. Pat. Nos. 2,347,310 and 2,409,932 disclose building block lifters having a handle and a non-movable portion insertable into the open cell of the building block. This is wedged between two walls defining the open cell, so as to enable the building block to be lifted by the worker. However, once such prior type tools are wedged in place, it is often difficult to remove them without damaging the block. Such damage, usually in the form of chipping, cause areas of weakness, which later on, after a period of use, undermine the strength of the entire block.
U.S. Pat. No. 2,808,286 discloses a cement block handling tool having movable and adjustable members so as to selectively lock and release the tool from the cement block, providing benefits over the prior art. However, the tool includes a movable plate and screws which must be adjusted for each type of block in order to securely hold and lift the block. Moreover, a wedge dog member, which pivots to engage the opposite surface of the cinder block, comes to a fairly sharp point. Thus, the cement block is held in place by contact of the ends of two bolts, and a pointed end of the dog wedge member, creating an insufficient frictional engagement. The sharp points can also dig into the relatively soft cinder or cement walls, damaging the cinder blocks and making removal of the tool difficult.
U.S. Pat. No. 4,463,979 discloses a building block handling tool as well. This tool is comprised generally of a U-shape member at the end of a handle which is inserted into an open cell of the cinder block. A plate is pivotally attached to the end of the member and deflected upwardly, depending upon the size of the cell. A curved portion of the member engages one inner side wall, and the edge of the plate, or edge of the member, engages the opposite side wall. However, this presents the problem of an insufficient frictional engagement with the side wall, and the potential for the sharp edge to dig into the cinder or concrete material, making removal of the tool difficult without damaging the block. Moreover, when the tool is inserted into the block's open cell, the handle is positioned at a very awkward upwardly directed carrying angle.
Another shortcoming of the aforementioned hand tools is that the cinder and concrete building blocks have changed in configuration over time. Instead of including three open cells, the newer cinder blocks only include two open cells. While the width of the building blocks vary from four inches to twelve inches (typically 4″, 8″, 10″ and 12″), and the thicknesses of the side walls can vary significantly, the length of the open cells have been found to be fairly consistent, with less than one-inch of variation between the major manufacturers.
Accordingly, there is a continuing need for a hand tool for lifting and carrying cinder and concrete building blocks. Such a hand tool should be configured and designed to accommodate the newer cinder blocks. Such a hand tool should also be relatively simple in design so as to be manufactured inexpensively and easily used. Such a hand tool should adequately frictionally engage the cinder block for lifting and carrying. Such a hand tool should also be adapted for lifting and carrying cinder blocks of different sizes. Such a hand tool should also be comfortably used by a mason or worker. The present invention fulfills these needs, and provides other related advantages.